Дисертації з теми "Chemical engineering, n.e.c"
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McAvoy, Camille Z. "Palladium-catalyzed C-N cross-coupling reactions toward the synthesis of drug-like molecules." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73388.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. ).
The development of methodologies for C-N bond formation reactions is an important scientific challenge because of many academic and industrial applications. This work will focus particularly on palladium-catalyzed cross-couplings of amine-containing compounds with aryl halides. The scope of the BrettPhos precatalyst for the cross-coupling of ortho-substituted aryl iodides with amides is studied using substrates with a variety of functional groups. Due to potential metal-chelating issues with some of the substrates used in this study, a proposed ligand synthesis is discussed in which one of the methoxy groups of BrettPhos is replaced with a morpholine capable of occupying palladium's open coordination site during its catalytic cycle. A final C-N bond formation study focuses on the cross-coupling of aryl halides with amidine salts. For this cross-coupling, a methodology has been developed that can be applied to various electron-rich, electron-poor, and electron-neutral substrates. Furthermore, the products of this cross-coupling can be used for a subsequent electrocyclization through a reaction with aldehyde, demonstrating that a relatively simple two-pot methodology can be used to make relatively complex substrates with pharmaceutical applications. Both amides and amidines are common moieties in drug-like molecules because of the various biological activities of these functional groups. Potential medicinal applications of the developed cross-coupling of amidine salts with aryl halides methodology are described. Thus, methodologies for various palladium-catalyzed, C-N cross-couplings as well as a potential ligand synthesis to be used for palladium catalysis are herein discussed.
by Camille Z. McAvoy.
S.B.
Bejarano, Roberto Villa. "An Investigation Into| I) Active Flow Control for Cold-Start Performance Enhancement of a Pump-Assisted, Capillary-Driven, Two-Phase Cooling Loop II) Surface Tension of n-Pentanol + Water, a Self-Rewetting Working Fluid, From 25 ?C to 85 ?C." Thesis, University of Nevada, Reno, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1565813.
Повний текст джерелаCold-start performance enhancement of a pump-assisted, capillary-driven, two-phase cooling loop was attained using proportional integral and fuzzy logic controls to manage the boiling condition inside the evaporator. The surface tension of aqueous solutions of n-Pentanol, a self-rewetting fluid, was also investigated for enhancing heat transfer performance of capillary driven (passive) thermal devices was also studied. A proportional-integral control algorithm was used to regulate the boiling condition (from pool boiling to thin-film boiling) and backpressure in the evaporator during cold-start and low heat input conditions. Active flow control improved the thermal resistance at low heat inputs by 50% compared to the baseline (constant flow rate) case, while realizing a total pumping power savings of 56%. Temperature overshoot at start-up was mitigated combining fuzzy-logic with a proportional-integral controller. A constant evaporator surface temperature of 60°C with a variation of ±8°C during start-up was attained with evaporator thermal resistances as low as 0.10 cm2–K/W. The surface tension of aqueous solutions of n-Pentanol, a self-rewetting working fluid, as a function of concentration and temperature were also investigated. Self-rewetting working fluids are promising in two-phase heat transfer applications because they have the ability to passively drive additional working fluid towards the heated surface; thereby increasing the dryout limitations of the thermal device. Very little data is available in literature regarding the surface tension of these fluids due to the complexity involved in fluid handling, heating, and experimentation. Careful experiments were performed to investigate the surface tension of n-Pentanol + water. The concentration and temperature range investigated were from 0.25%wt. to1.8%wt and 25°C to 85°C, respectively.
Kanuru, Vijaykumar. "Understanding surface mediated C-C and C-N bond forming reactions." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608956.
Повний текст джерелаPorada, O. K., A. O. Kozak, V. I. Ivashchenko, S. M. Dub, Олександр Дмитрович Погребняк, Александр Дмитриевич Погребняк, and Oleksandr Dmytrovych Pohrebniak. "Hard Si-C-N Chemical Vapor Deposited Films." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42711.
Повний текст джерелаQian, Xin. "Cobalt-Catalyzed C-C and C-N Coupling reactions." Phd thesis, Ecole Polytechnique X, 2013. http://pastel.archives-ouvertes.fr/pastel-00943479.
Повний текст джерелаSmith, Gordon Christopher. "Catalytic cracking of n-alkanes and n-alkylbenzenes over H-ZSM-5 zeolite." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12550.
Повний текст джерелаGunnarsson, Sophie. "Optimisation of N release : influence of plant material chemical composition on C and N mineralisation /." Uppsala : Dept. of Soil Sciences, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a381.pdf.
Повний текст джерелаGooseman, Natalie. "The influence of the C-N⁺------F-C charge dipole interaction in fluoro organic chemistry /." St Andrews, 2008. http://hdl.handle.net/10023/695.
Повний текст джерелаLin, Xufeng. "Density functional theory studies of selected transition metals catalyzed C-C and C-N bond formation reactions." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39359645.
Повний текст джерелаWang, Luo. "Excess enthalpies and excess volumes for n-butyl methyl ether + n-alkane systems at 298.15 K." Thesis, University of Ottawa (Canada), 1990. http://hdl.handle.net/10393/5686.
Повний текст джерелаLin, Xufeng, and 林旭鋒. "Density functional theory studies of selected transition metals catalyzed C-C and C-N bond formation reactions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39359645.
Повний текст джерелаIvashchenko, V. I., P. L. Scrynskyy, A. I. Kuzmichev, L. A. Ivashchenko, O. Yu Khyzhun, I. I. Timofejeva, O. O. Butenko, and V. M. Granko. "Characterization of Ti-B-C-N Nanocomposite Coatings." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35053.
Повний текст джерелаPope, Christopher James. "A chemical mechanism for fullerenes C₆₀ and C₇₀ formation with kinetic modeling of their synthesis in flames." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12663.
Повний текст джерелаCowley, Michele. "Conversion of n-pentenes over H-ZSM-5." Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/5370.
Повний текст джерелаThe skeletal isomerisation of I-pentene provides the feed stock 2-methyl-2-butene and 2-methyl-I-butene for the production of tertiary amyl methyl ether (TAME), an octane booster for petrol. Benzene, toluene, xylenes and ethylbenzene (BTX+EB) are good or even better octane boosters, although the use of benzene is limited due to its carcinogenic nature. From an industrial point of view, these compounds are therefore of importance. The conversion of I-pentene over H-ZSM-5 zeolite catalyst was studied in a fixed-bed micro reactor.
Al-Damkhi, Ali M. "Separation of n-paraffins by selective adsorption." Thesis, Aston University, 1986. http://publications.aston.ac.uk/10192/.
Повний текст джерелаSafoniuk, Michael. "A thermogravimetric study of the Si-O-N system /." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61045.
Повний текст джерелаModak, Viraj Prakash. "Surface Freezing in n-Alkanes: Experimental and Molecular Dynamics Studies." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1449013699.
Повний текст джерелаKoen, Matthew Anthony. "Hydrocracking of long chain n-Paraffins under Fischer-Tropsch conditions." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13260.
Повний текст джерелаA number of various iron-palladium loaded H-MFI zeolites used for the hydrocracking of n- hexadecane under Fischer-Tropsch conditions were tested to address the inherent low CO tolerance of the pure palladium noble metal hydrocracking catalysts. The hydrocracking mechanism consists of two functions, namely the metal de-/hydrogenation (HD/DHD) and the acidic -scission function. The addition of CO to reactions involving monometallic palladium hydrocracking catalysts has led to an imbalance between these functions due to the migration of the noble metal resulting in significant and undesirable secondary cracking. However, the inclusion of iron to the hydrocracking catalyst may allow for chemical anchoring of the noble metal (Wen et al., 2002) reducing the effect of the migration and thus retaining the bifunctional balance. The consequent palladium-iron alloy (Garten, 1976) also has the potential for an improved rate of de-/hydrogenation (Fukuoka et al., 1990) resulting in a greater rate of intermediary carbenium ions which in turn could lower any undesired secondary cracking reactions already present. The Fe/H-MFI precursor was prepared using a solid-state ion exchange after which incipient wetness impregnation was used to add the palladium. Different loadings of palladium and iron were used to prepare the PdFe/H-MFI catalysts in order to determine an optimum ratio loading. All experiments were conducted at standard low temperature Fischer-Tropsch conditions in a plug-flow fixed trickle-bed reactor equipped with a homogeneously operating evaporator and on-line GC-FID analysis. It was found that none of the bimetallic catalysts produced showed any greater tolerance to carbon monoxide when compared to the monometallic catalyst. The results indicated that the behaviour of the bimetallic catalyst was near identical to that of the monometallic catalyst in the presence of CO. It was thus concluded that the preparation method used, in particular the Fe/H- MFI precursor through solid state ion-exchange, was unsuitable for the production of an alloyed PdFe/H-MFI catalyst. An effect of iron was noted in the low palladium high iron loaded catalyst i.e. PdFe/H-MFI (16,12). In the absence of CO, this catalyst showed a significantly improved selectivity when com- pared to the low palladium low iron catalyst, PdFe/H-MFI (16,24). This effect of iron was attributed to the blockage of the H-MFI pores due to the large amount of iron present. As a consequence of this, access to the internal acid sites is severely limited and therefore are essentially removed from the hydrocracking reaction. As such the PdFe/H-MFI (16,12) has an improved metal:acid site balance. Poisoning by water (a Fisher-Tropsch product) was found to significantly reduce secondary cracking due to deactivation of the acid sites (lowering of total acidity) resulting in improved selectivity through intermediary olefin product promotion. From this, almost pure primary cracking was possible allowing the noble metal catalysts to retain its ideal hydrocracking properties at very high conversions (as evident by the high isomerization selectivity). This indicates that if the total acid strength of the H-MFI zeolite could be reduced (e.g. dealumination), the overall catalyst selectivity could be improved. Testing into whether the effect of water in reducing secondary cracking could be used to offset the effect of an increase in secondary cracking by CO addition, proved ineffective. It is therefore thought that CO not only causes palladium migration and clustering on the external zeolite but also poisons the active metal sites still available. As a result the balance between the metal and acid function could not be restored. It is thus recommended that for future work a zeolite with a lower total acid strength be used in conjunction with a alternate method for iron addition. Furthermore, testing into higher loadings of palladium may prove fruitful in balancing its migratory nature in the presence of carbon monoxide.
Drouillard, Ken G. "Physico-chemical property determinations of chlorinated n-alkanes, C¦10 to C¦12, parameters for estimation of the environmental fate of chlorinated n-paraffins." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq23287.pdf.
Повний текст джерелаBinneman, Jacqueline. "The hydrocracking of long chain n-paraffins under Fischer-Tropsch conditions." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/14415.
Повний текст джерелаInterest in the area of hydrocracking has grown rapidly over the years. In the early 1960's companies such as Chevron and Universal Oil Products (UOP) introduced new hydrocracking processes to manufacture high octane gasoline. The demand for transportation fuels such as diesel and jet fuel has increased significantly which results in the continuous development of hydrocracking techniques and catalysts. The conversion of normal long chain paraffins from the Fischer-Tropsch synthesis to clean distillate fuels is a particular area of interest. The objective of this project is to investigate the hydrocracking of long chain paraffins under F-T conditions. The aim is to achieve in situ, the hydrocracking of low temperature Cobalt-based F-T wax by combining F-T synthesis and hydrocracking in a single reactor. For the purpose of this thesis, it involves subjecting the hydrocracking catalyst to F-T conditions. Synthesis gas (carbon monoxide and hydrogen), the paraffin n-C16 and water were co-currently fed to a fixed-bed reactor containing only the hydrocracking catalyst. Therefore care was taken to match the experimental conditions of the hydrocracking experiments to those that prevail in the Fischer-Tropsch synthesis. Practically this means the hydrocracking of n-hexadecane was studied at the space velocity, the reaction temperature and pressure and under partial pressure of H2, CO and water, at which n-hexadecane is produced in F-T process assuming that n-hexadecane is the only hydrocarbon product and that n-hexadecane is a model compound for the low temperature F-T process. The results of this investigation show that the hydrocracking reaction over a Pd catalyst supported on H-MFI Zeolite under F-T conditions is non-ideal. At low feed (n-C16) conversions, product distributions are strongly dominated by secondary reactions. The ability of the metal site is significantly inhibited by the presence of CO and water. The product distributions show exactly this due to the increase in unsaturated and more branched species. Feed conversion in the presence of water and CO increase with increasing reaction temperature. The absence of methane in the product spectrum is an indication that the hydrogenolysis reaction is an unfavorable pathway for the catalyst used. The data obtained from this investigation suggests that the combination of low temperature Fischer-Tropsch and hydrocracking into a single reaction step is feasible.
Hop, Marina. "Dehydrogenation of N-Propanol to Propionaldehyde over a copper chromite catalyst." Master's thesis, University of Cape Town, 1998. http://hdl.handle.net/11427/18796.
Повний текст джерелаKoffas, Mattheos A. G. "Metabolic engineering of C. glutamicum for amino acid production improvement." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/8745.
Повний текст джерелаIncludes bibliographical references (leaves 183-210).
A central goal in metabolic engineering is the design of more productive biological systems by genetically modifying metabolic pathways. In this thesis we report such an optimization in the bacterial strain Corynebacterium glutamicum that is employed for the fermentative production of various amino acids such as lysine. The main goal of the research presented here was the application of metabolic and genetic engineering tools in order to investigate the role of the pyruvate node in cellular physiology. This was achieved by integrating the tools of bioinformatics, recombinant DNA technology, enzymology and classical bioengineering in the context of control and genetically engineered strains of C. glutamicum. First, the main anaplerotic pathway responsible for replenishing oxaloacetate, namely pyruvate carboxylase was targeted. After fruitless attempts to establish an in vitro enzymatic activity for this enzyme, our efforts were directed towards its gene identification. This was achieved by designing PCR primers corresponding to homologous regions among pyruvate carboxylases from other organisms. Utilizing these primers, a PCR fragment was isolated corresponding to part of the gene of the C. glutamicum pyruvate carboxylase. The sequence of the complete gene was finally obtained by screening a C. glutamicum cosmid library. In order to investigate the physiological effect that this enzyme has on lysine production, recombinant strains and deletion mutants were generated. The presence of the gene of pyruvate carboxylase in a multicopy plasmid is not sufficient to yield a significant overexpresssion of this enzyme in C. glutamicum. Contrary to our expectations, overexpression of pyruvate carboxylase has a negative effect on lysine production but improves significantly the growth properties of C. glutamicum. A metabolic model was developed according to which pyruvate carboxylase overexpression increases the carbon flux that enters the TCA cycle, thus the higher growth. However due to the presence of a rate-limiting step in the lysine biosynthesis pathway this increased carbon flux does not translate into higher lysine production. The role of aspartokinase, the first step in lysine biosynthesis, was explored as such a potential bottleneck. Its overexpression proves to increase the amount of lysine produced, however it leads to a lower growth and finally a lower productivity. Since pyruvate carboxylase and aspartokinase have opposite effects on cell physiology, the combination of the overexpression of these two enzymes was finally studied. By this simultaneous overexpression, we achieved to create a C. glutamicum recombinant strain with similar growth as that of the control but higher lysine production and productivity. In the context of exploring the physiological role of pyruvate carboxylase, a biotinylated enzyme, two other enzyme that utilize biotin were also investigated namely acetyl-CoA-carboxylase and biotin ligase. The first enzyme was purified to completion and its N-terminal as well internal amino acid sequences were obtained. A cosmid from the C. glutamicum cosmid library was identified that most likely contains the gene of the latter enzyme. In summary, in the present work we have achieved to prove unequivocally the presence of pyruvate carboxylase in C. glutamicum. We have also achieved to characterize the second biotinylated enzyme in this organism, namely acetyl-CoAcarboxylase. The physiological effect of both pyruvate carboxylase and aspartokinase was established and a metabolic model was developed based on these experimental results. This model finally led us to the construction of a new recombinant strain with improved lysine productivity. As such, this work stands as one of the few examples of a primary metabolite production improvement using metabolic engineering techniques.
by Mattheos A.G. Kofas.
Ph.D.
Chen, Tianyi. "Production of n-Butanol by Clostridium Carboxidivorans." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1556309785594048.
Повний текст джерелаWasylenko, Thomas M. (Thomas Michael). "¹³C-metabolic flux analysis of recombinant yeasts for biofuels applications." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98717.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references.
Fossil fuels have powered the transportation industry since the Industrial Revolution. However, rising transportation energy demand and new knowledge about the environmental impact of burning fossil fuels have motivated the development of technologies for sustainable production of renewable, carbon-neutral liquid fuels. To that end, biological systems may be leveraged to fix carbon dioxide and to catalyze the conversion of renewable feed stocks to fuel molecules. Today, the gasoline additive ethanol and biodiesel are produced by yeast fermentation of sugars derived from cornstarch and sucrose and transesterification of vegetable oils, respectively. However ethanol has many drawbacks as a fuel additive, and both biofuels are currently produced from edible feed stocks. For biofuels to contribute significantly to meeting total transportation energy demand, processes for production of fuel molecules from non-food feed stocks must be engineered. Two promising solutions are fermentation of sugars derived from "woody," lignocellulosic biomass and production of fuels from volatile fatty acids (VFAs) such as acetate, which can be produced by fermentation of organics in municipal solid waste and sewage or syngas. The production of biofuels from lignocellulosic material or VFAs will require metabolic engineering of biocatalysts to improve yields, productivities, and final titers. These metabolic engineering efforts can be facilitated by ¹³C-Metabolic Flux Analysis (MFA), a method for elucidating the otherwise unobservable intracellular metabolic fluxes in biological systems. We first developed protocols for extraction and LC-MS/MS analysis of intracellular metabolites, which provides data that may be used for metabolic flux estimation. We then performed an analysis of both the measurement and modeling errors associated with using these data for flux determination. Finally, we applied ¹³C-MFA to two industrially relevant systems: 1) Fermentation of xylose, a sugar present in lignocellulosic biomass, to ethanol in Saccharomyces cerevisiae, and 2) overproduction of fatty acids that may be transesterified to biodiesel from either glucose or acetate in the oleaginous yeast Yarrowia lipolytica. These experiments identified a potential bottleneck in xylose fermentation in S. cerevisiae and the primary source of NADPH for fatty acid biosynthesis in Y. lipolytica, and also suggested potential strategies for improving lipid yields in Y. lipolytica.
by Thomas M. Wasylenko.
Ph. D.
Piallat, Fabien. "Plasma assisted chemical deposition (CVD/ALD) and integration of Ti(Al)N and Ta(Al)N for sub-20 nm metal gate." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT015/document.
Повний текст джерелаFor the sub-20 nm technological nodes metal conformity requirements are beyond the possibilities of the currently used PVD deposition technique. CVD techniques, more specifically MOCVD and ALD, are identified as the best techniques for metal deposition. For metal-gate application, titanium and tantalum carbo-nitrides alloys are considered as the most promising. In this work, a detailed review of MOCVD and ALD deposition mechanisms and plasma influence on the deposited material is carried out. First, process windows for successful tuning of the metal properties are examined. Plasma impact on the metal and the inherent reaction mechanisms are also highlighted with the help of plasma characterisation. Then great importance is given to the integration of these metals, by careful study of the interactions taking place at the interfaces. Correlations between physico-chemical properties and electrical behavior of the metal/high-k dielectric stack are introduced thanks to XPS characterisation. Finally, aluminium doping of MOCVD TiN and TaN is considered for n-mos and p-mos gate characteristics achievement. By comparison of the properties and behaviours of Al doped metals deposited by PVD and MOCVD, diffusion mechanisms are proposed to explain the role of Al in the observed changes
Kukard, Ross S. "The effect of zeolite type on the hydrocracking of long n-paraffins." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5301.
Повний текст джерелаIncludes bibliographical references (leaves 141-144).
Although it is debatable as to the lifetime of the planet’s crude oil reserves, it is indisputable that they are finite and will, eventually, become exhausted. As such it is desired to devise methods whereby currently available non-crude oil derived hydrocarbon feedstocks may be utilised for the production of clean, high quality liquid fuels (particularly middle distillate fuels such as diesel and jet fuel), aiding in alleviating the demand on crude oil reserves. One technique whereby this may be achieved involves the conversion of the non-crude oil derived hydrocarbon feedstock (for example stranded gas, remote natural gas, coal or biomass) to syngas (a mixture of CO and H2). This syngas is subsequently converted to paraffinic wax by Fischer-Tropsch Synthesis, and this wax selectively hydrocracked down to the desired distillate fuels fraction. This hydrocracking may be conducted utilising either monofunctional or bifunctional catalysts. Monofunctional catalysts, such as the supported sulphided base metals or metal oxides utilised in many crude oil refineries, yield a product with minimal additional branching, as desired, though would contaminate the otherwise clean Fischer-Tropsch wax with sulphur. Bifunctional catalysts, utilising a metal on an acidic support, yield a product with significant branching, yet do not contaminate the product. Furthermore, the acid supports utilised in oil refinery applications are limited to either amorphous silica-alumina, or H-USY (a thermally treated large pore zeolite) due to the presence of large, bulky polycyclic and highly branched molecules in the feedstock. Fischer-Tropsch wax exhibits only minimal branching, and it was hence the aim of this investigation to determine whether zeolites with pores smaller than those utilised in the hydrocracking of crude oil derived feedstocks, specifically medium pore zeolites such as H-MFI, may be utilised in the bifunctional hydrocracking of this wax to impart shape selectivity upon the reaction, thereby limiting the extent to which branching may occur. In this regard, four different zeolites (H-MFI, H-BEA, H-USY and H-MOR) were tested under the same, industrially relevant conditions, and the results collated so as to quantify the effects of the each zeolite’s unique properties, in particular their pore geometries (in terms of pore size, shape and channel inter-connectivity), the performance of each catalyst in terms of its activity (the overall conversion of the feedstock) and selectivity (with regards to both carbon number distribution and the degree of branching). Furthermore, it was desired to determine the extent to which the anticipated transition state shape selectivity of some of the zeolites affected the stability (on-stream lifetime) of the catalyst through a reduction in coke formation. The results of this investigation indicated that medium pore zeolites show significant potential for use in the selective hydrocracking of a Fischer-Tropsch wax feedstock. It was found that those zeolites possessing medium sized pores (specifically H-MFI and H-BEA) exhibited a significantly higher activity than did those with only larger pores (H-USY and H-MOR), a phenomenon theorised to be due to the more orderly and efficient configuration of the adsorbed molecules within the medium pores promoting contact with active acid sites. Furthermore, it was found that H-MFI, with a porous network comprised entirely of medium pores, showed an improved selectivity towards the desired linear products, whilst zeolites with only wide pores (H-USY and H-MOR) and those with intersecting wide and medium pores (H-BEA) showed branched product selectivities roughly equivalent to one another, all greatly favouring the production of mono-methyl branched species. Unfortunately, due primarily to the large variations in the observed activity between the zeolites tested, the results of the deactivation analysis were inconclusive.
Fiaz, Mohammed. "Dipole moments and Kerr effect of poly(n-vinylcarbazole) and its complexes with trinitrofluorenone." Thesis, Aston University, 1994. http://publications.aston.ac.uk/9697/.
Повний текст джерелаKotsiopoulos, Athanasios. "The hydrocracking of Fischer-Tropsch wax : using n-tetradecane as a model compound." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/8662.
Повний текст джерелаIncreasingly stringent legislation has been applied to transportation fuels to minimise or eliminate aromatics and sulphur compounds in diesel fuel. This has led to manufacturers determining alternative production methods to comply to legislation. Part of the current diesel fuel is being produced by hydrocracking heavier fractions derived from crude oil. These hydrocracking processes utilise bi-functional catalysts which have a metal (hydrogenating/dehydrogenating) function and an acid (cracking) function. The most common of these hydrocracking catalysts are combinations of either noble metals and acid zeolites, such as Pt/ HY, or combined sulphides of group VIA and VIIIA metals on amorphous acidic supports, such as CoMo/SiO2-Al2O3. For good quality diesel, the fuel should have a high cetane number and the aromatics and sulphur content should also be kept to a. minimum (e.g. EU legislation: sulphur content must be below 10 ppm (wt) by 2008). Fischer-Tropsch wax is made up predominantly of long-chain linear paraffins with exceptionally low aromatics and heteroatom content (sulphur and nitrogen-containing compounds) and therefore a good source for very 'clean', good quality diesel. The objective of this study was therefore to investigate the suitability of a conventional bi-functional hydrocracking catalyst namely, CoMo/SiO2-Al2O3 in unsulphided form for the hydrocracking of Fischer-Tropsch wax using n-tetradecane as a model compound. The purpose of using the catalyst in unsulphided form was not to introduce any sulphur to the already sulphur-free feedstock.
Noorani, Khalid. "Comparative chemical kinetic and experimental study of methanol, ethanol, n-propanol and n-butanol auto-ignition delay times." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106391.
Повний текст джерелаDans cette these, des melanges de methanol, ethanol, n-propanol et n-butanol avec de l'air synthetique sont exploses derriere une onde de choc reflechie a haute temperature (1070K-1760K) ou les temps de retard a l'allumage sont mesures a differents taux d'equivalences, dilutions, pressions et temperatures pour etablir les points de similitaritees et differences entre alcools. Beaucoup d'etudes ont ete fait pour modeliser et comprendre l'oxydation de ces derniersmais les etudes n'ont pas ete realise de maniere comparative. Ainsi, ce travail presente une etude comparative des temps de retard d'allumage des alcools simples (C1 a C4). Les resultats ont indique que ces combustibles ont des temps de retard d'allumage comparables, ce qui indique une similitaritee des voies d'oxydation des differents alcools.Des modeles cinetiques trouves dans la litterature sont compares aux resultats experimentaux. Il se trouve que celui de Marinov (1998) est le plus proches des valeurs mesurees. De plus, des analyses de dependance des taux de reactions sur les delais d'allumage sur ces modeles indiquent la dominance des reactions a base de radicaux.
Nelson, Peter Jonathan. "Boiling the immiscible water/n - nonane system from a tube bundle." Thesis, Heriot-Watt University, 1986. http://hdl.handle.net/10399/1060.
Повний текст джерелаEwing, Helen Clifford. "The nucleation and growth mechanisms of amorphous Si-N-O fibres." Thesis, University of Strathclyde, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366923.
Повний текст джерелаKelly, Mark. "Laser diagnosis and computer modelling of C/H/O and C/H/N plasmas used in diamond chemical vapour deposition." Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.653079.
Повний текст джерелаGlaves, L. R. "The recovery of precious metals from aqueous solutions using heterocyclic N-oxides." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356757.
Повний текст джерелаEsalah, Jamaleddin. "Removal of heavy metals from aqueous solutions by precipitation with sodium di-(n-octyl) phosphinate." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37715.
Повний текст джерелаThe heavy metals lead, cadmium, and zinc were precipitated from aqueous solutions with sodium di-(n-octyl) phosphinate (NaL) in the form of PbL 2(s), CdL2(s), and ZnL2(s). The mole ratio of NaL to lead in the feed was varied from 0.1 to 6.5, depending on the acidity of the feed. The effects of the feed pH, concentration of chloride, concentration of calcium, and of the chain length of the precipitating agent on the removal of lead, were investigated. Adding acid to the feed solution reduced the removal of lead as some of the phosphinate precipitated in the acid form as HL(s). The presence of chloride or calcium in the feed solution, up to mole ratios to lead of 250 and 2.75, respectively, had no effect on the removal of lead. The solubility of the precipitate PbL 2(s) was reduced by increasing the length of the alkyl group of the phosphinate. The removal of cadmium, zinc, and a mixture of lead, cadmium and zinc was investigated. Behavior similar to that of lead was observed. The selectivity of the precipitating agent for the three metals was in the order Zn > Pb > Cd.
The precipitating agent was completely regenerated by adding NaOH to the precipitate, and then contacted with diethyl ether to extract the reagent. The lead was completely recovered from the PbL2(s). Pure lead-free precipitating agent, and an aqueous solution of lead at a concentration 100 times its concentration in the feed, were obtained.
Using measured solubility products of the precipitates and literature values of the stability constants for the other expected reactions, the removal of metal, the loss of precipitating agent, and the equilibrium pH were predicted.
Chede, Sneha A. "Fouling Control Using Temperature Responsive Membranes composed of N-isopropylacrylamide (NIPAAm) and Iron Oxide Nanoparticles." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1449426051.
Повний текст джерелаDu, Yinming. "High-Yield and High-Titer n-Butanol Production from Lignocellulosic Feedstocks by Metabolically Engineered Clostridium tyrobutyricum." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374193011.
Повний текст джерелаQuan, Congling Soroush Masoud Grady Michael. "High-temperature free-radical polymerization of n-butyl acrylate /." Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/553.
Повний текст джерелаMarshall, Brian A. "Immediate C-terminal Extein Effects on the Cleaving Kinetics of the ¿I-CM Mini-Intein." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1532363837193988.
Повний текст джерелаHe, Jiliang. "Silyhydrazines : chemistry and pyrolytic conversion to Si-N-C ceramic materials." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29044.
Повний текст джерелаAli, J. A. M. "Liquid-phase adsorption of n-paraffins on type 5A molecular sieves." Thesis, Aston University, 1987. http://publications.aston.ac.uk/9700/.
Повний текст джерелаBao, Teng. "Metabolic engineering of Clostridium cellulovorans for selective n-butanol production from cellulose." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574686346943506.
Повний текст джерелаDe, Vries Christian. "Adding ammonia during Fischer-Tropsch Synthesis: Pathways to the formation of N-containing compounds." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25269.
Повний текст джерелаFournier, Martin. "Reactivity of C₃N and C₂H at low temperature : applications for the Interstellar Medium and Titan." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S100/document.
Повний текст джерелаThe interstellar medium and some atmospheres of planetary bodies, in particular Titan, one of the largest satellites of Saturn, present a large variety of chemical species. This complex chemistry is very different from the one we know on Earth. To understand the global phenomenon that happen in these environments, we need to understand the chemical reactions, their reaction rate and their products. With the CRESU technique, we are able to reproduce partially the coldest environments of space to study these reactions
Jackson, Colleen. "SiC and B₄C as electrocatalyst support materials for low temperature fuel cells." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27313.
Повний текст джерелаJackson, Colleen. "Preparation and characterisation of Pt-Ru/C catalysts for direct methanol fuel cells." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/24322.
Повний текст джерелаMaalouf, Manale W. "Structure and Dynamics Influencing Proton Transport in Materials for High Temperature (120 °C) PEM Fuel Cells." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1311010188.
Повний текст джерелаYuan, Hongyu. "Optimization of an Innovative Npu-N Resin Production." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555591103161637.
Повний текст джерелаVan, der Walt Franschua Johan. "Factors influencing the catalytic activity of Fe-ZSM-5 during the catalytic conversion of N₂O." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/24323.
Повний текст джерелаBertrand-Caumont, Karine. "Conception et synthèse de N. C. E. (New Chemical Entities), ligands des récepteurs NK1 de la substance P." Lille 1, 1996. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1996/50376-1996-262-1.pdf.
Повний текст джерелаHlabangana, Ntandoyenkosi. "Influence of particle size and morphology of Pt₃Co/C on the oxygen reduction reaction." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/24324.
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